Mask off FS_EVENT_ON_CHILD in dnotify_handle_event(). Otherwise, when there
is more than one watch on a directory and dnotify_should_send_event()
succeeds, events with FS_EVENT_ON_CHILD set will trigger all watches and cause
spurious events.
This case was overlooked in commit e42e2773.
Signed-off-by: Andreas Gruenbacher <[email protected]>
---
fs/notify/dnotify/dnotify.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index 828a889..0a8f1de 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -106,7 +106,7 @@ static int dnotify_handle_event(struct fsnotify_group *group,
spin_lock(&entry->lock);
prev = &dnentry->dn;
while ((dn = *prev) != NULL) {
- if ((dn->dn_mask & event->mask) == 0) {
+ if ((dn->dn_mask & event->mask & ~FS_EVENT_ON_CHILD) == 0) {
prev = &dn->dn_next;
continue;
}
--
Test case demonstrating the bug:
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
static void create_event(int s, siginfo_t* si, void* p)
{
printf("create\n");
}
static void delete_event(int s, siginfo_t* si, void* p)
{
printf("delete\n");
}
int main (void) {
struct sigaction action;
char *tmpdir, *file;
int fd1, fd2;
sigemptyset (&action.sa_mask);
action.sa_flags = SA_SIGINFO;
action.sa_sigaction = create_event;
sigaction (SIGRTMIN + 0, &action, NULL);
action.sa_sigaction = delete_event;
sigaction (SIGRTMIN + 1, &action, NULL);
# define TMPDIR "/tmp/test.XXXXXX"
tmpdir = malloc(strlen(TMPDIR) + 1);
strcpy(tmpdir, TMPDIR);
mkdtemp(tmpdir);
# define TMPFILE "file"
file = malloc(strlen(tmpdir) + strlen(TMPFILE) + 2);
sprintf(file, "%s/%s", tmpdir, TMPFILE);
fd1 = open (tmpdir, O_RDONLY);
fcntl(fd1, F_SETSIG, SIGRTMIN);
fcntl(fd1, F_NOTIFY, DN_MULTISHOT | DN_CREATE);
fd2 = open (tmpdir, O_RDONLY);
fcntl(fd2, F_SETSIG, SIGRTMIN + 1);
fcntl(fd2, F_NOTIFY, DN_MULTISHOT | DN_DELETE);
if (fork()) {
creat(file, 0600);
/* Spurious event triggered below! */
unlink(file);
} else {
sleep(1);
rmdir(tmpdir);
}
return 0;
}
On Sun, 2009-10-18 at 14:46 +0200, Andreas Gruenbacher wrote:
> Mask off FS_EVENT_ON_CHILD in dnotify_handle_event(). Otherwise, when there
> is more than one watch on a directory and dnotify_should_send_event()
> succeeds, events with FS_EVENT_ON_CHILD set will trigger all watches and cause
> spurious events.
Added to my linus tree last night (along with a couple other fixes) will
push it public and ask him to pull when I finish testing.
-Eric
On Sunday, 18 October 2009 17:52:10 Eric Paris wrote:
> Added to my linus tree last night (along with a couple other fixes) will
> push it public and ask him to pull when I finish testing.
Thanks.
Andreas